A method of this kind is disclosed in the international application having the publication No. WO 95/17128. In this previously known method, the means used for interconnecting the two vessels consisted of an open springy brace carrying spikes and being capable of being bent elastically so as to make its free ends cross each other, said spikes forming angles with the brace gradually diminishing from acute angles at the free ends to substantially right angles mid-way between them. When released from the anastomotic instrument holding the brace in the elastically bent condition, it would bring the spikes into engagement with the regions to be joined so as to penetrate the latter and so to speak nail them together.
Extra-clinical trials have, however, shown that one can not always be certain that all the spikes have penetrated through the parts concerned of the two vessels to be joined, this probably being due to the limited elastic force available from the springy brace.